Genetic analysis of fusarium wilt resistance in Upland cotton germplasm (Gossypium hirsutumL.)

Fusarium wilt (FW), caused by the soil-borne pathogen Fusarium oxysporum f. sp. vasinfectum (FOV), is an economically serious disease-causing significant damage to cotton crops worldwide, including in Uzbekistan. This study evaluated the resistance of Upland cotton (Gossypium hirsutum L.) germplasm from Uzbekistan against FOV race 4 under controlled phytotron conditions. Fifteen cotton accessions were phenotypically assessed for disease symptoms and genotypically screened with 118 simple sequence repeat (SSR) markers to identify genetic polymorphisms. Several cotton lines, including Rex, PD−648, Mebane B−1, Las Brenas−347, and DPZ−554085, exhibited high resistance to FW. A total of 40 SSR markers were polymorphic, producing 165 alleles. The identification of resistant lines possessing specific resistance-associated marker alleles provides valuable genetic resources. These findings can be effectively utilized in marker-assisted selection (MAS) to accelerate the development of high-yielding, wilt-resistant cotton cultivars. Uzbekistan's primary commercial cotton variety, Bukhara−6, is highly susceptible to the destructive Fusarium wilt pathogen (FOV4), risking national cotton production. Policy should promote the prompt development and distribution of resistant cultivars to prevent significant economic losses. This study identifies several highly resistant cotton lines, including Rex, PD−648, and Mebane B−1, within the national germplasm. These lines represent valuable genetic resources that should be quickly integrated into public breeding programs to enhance the resilience of the national cotton crop. Validated DNA markers associated with FOV4 resistance can now support marker-assisted selection (MAS). This advanced breeding technology will speed up the development of high-yielding, resistant varieties, ensuring a sustainable and profitable future for Uzbekistan's essential cotton industry.